Tape punch

ABSTRACT

A high speed solenoid operated punch for paper tape or the like in which a relatively weak spring is provided to normally hold the punch in retracted position and to take up clearances in the punch linkage. A second stiffer, cantilever type spring is engaged by the punch linkage only after the punch has partially sheared through the tape and, finally, a much stiffer cantilever type spring is engaged after the punch passes completely through the tape to arrest the punch and to catapult the same back to its retracted position, aided by the second spring.

o United States Patent 1 [111 3,724,309 Takenaka [4 1 Apr. 3, 1973 54 TAPE PUNCH 3,465,958 9/1969 Gunderson etali ..s3 575 x Inventor: George Takenaka, Santa Anna 2,968,982 1/196! Cousmo ..83l588 X Cahf Primary Examiner-Andrew R. Juhasz [73] Assignee: Addmaster Corporation, San Assistant -J mes F- Coan Gabriel, Calif. AttrneyFred N. Schwend PP 134,354 A high speed solenoid operated punch for paper tape or the like in which a relatively weak spring is pro- 52 us. Cl. ..s3 s75 83 588,83 590 "ided mmally the Punch rammed Positiml 1 l l l and to take u clearances in the unch linkage. A [51] Int. Cl. ..B26d /06 p 58 Field of Search ..s3/5ss 589,590 575 "mevmype sprmgsengaged bythe punch linkage only after the punch has partially [56] References Cited sheared through the tape and, finally, a much stiffer cantilever type spring is engaged after the punch UNITED STATES PATENTS passes completely through the tape to arrest the punch and to catapult the same back to its retracted-position, Vogel Ct al. X aided the econd pring 3,064,881 ll/l962 Davy et a] ..83/575 X 3,056,546 10/1962 Zenner ..83/575 X 11 Claims, 5 Drawing Figures v:l82l I6 22 F l 9 -v 'I A* /2 38 52 5 4 /7 8 5! T3 41 3% 37 T ;f- 1 1 451 5 11 l T 2 a4 2 Z2 Z3 27 TAPE PUNCH BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to high speed punches for punching code designations in paper tape, cards or other record material.

2. Description of the Prior Art Heretofore, in order to reduce the cost of construction and to simplify the mechanism, punches of the above type have been proposed embodying solenoids for directly actuating the punches. Generally, in such cases, the solenoid operates continually against the force of a punch retracting spring which must be strong enough to return the punch and associated mechanism into retracted position. In attempting to increase the speed of operation of such punches it has been found that the strength of the retracting springs must be made increasingly stronger in order to reduce the time necessary to retract the punches. Consequently, the solenoids must be made larger and more electric current must be passed therethrough to overcome the retracting spring forces and to also decrease the time for advancing the punches so that overheating of the solenoid becomes an additional problem. Also, the provision of positive stopping means for arresting each punch as it passes through the tape results in considerable noise, wear and vibration.

Attempts to overcome the above difficulties have resulted in the use of complicated linkages which defeat the aim of simplicity or by the use of additional retracting solenoids such as disclosed in US. Pat. to Svidercoschi No. 3,040,610. Such expedients increase the cost and complexity of the punch mechanism and require critically controlled timing devices for sequentially operating the advancing and retracting solenoids, especially as higher speeds are attempted.

SUMMARY OF THE INVENTION The present invention overcomes the above problems while resulting in a simple, reliable and economically manufactured punch mechanism by providing a three stage spring system including a relatively weak spring capable mainly of normally holding the punch in retracted position and of taking up backlash or clearances in the punch linkage. A second stiffer retracting spring is brought into action only when thepunch has penetrated partly through the tape, and finally, a third and much stronger stiffer spring is brought into action when the punch passes completely through the tape to arrest the same and to impel the punch and its linkage back to retracted position. The second spring also aids in returning the punch linkage and insures that the punch is withdrawn from the tape.

Accordingly, the solenoid is enabled to accelerate the punch toward the tape at a high rate against only the relatively weak retaining spring. Thus, it is substantially unimpeded until sufficient momentum is achieved to enable the punch to penetrate the tape, aided by the drive of the solenoid, and when the punch is partly through the tape, the second spring commences to decelerate the same. Finally, as the punch emerges through the tape the third and far stronger retracting spring not only arrests the punch linkage but, aided by the second spring, catapults the same toward retracted position. This enables relatively small solenoids to be employed without danger of overheating during high speed operation and also allows a group of such solenoids to be closely packed together.

A further feature of the invention is the arrangemen whereby the punch advancing and retracting forces are applied substantially in line with the path of movement of the punch to reduce frictional loads which might otherwise be developed in pivotal bearings, camming surfaces or the like when the actuating forces are not in line with the movement of the punch.

A still further feature of the invention resides in the provision of a lever intermediate certain of the punch linkage for co-acting with the various springs, the lever being connected to the linkage and coacting with the springs on the side of the pivot point of the lever nearest the tape so that no binding or twisting tendency will be set up in the lever bearing which would otherwise impose unwanted frictional loads on the solenoid. Accordingly, the need for bearing hubs or the like is obviated, permitting a plurality of such levers to be arranged in close proximity to each other and reducing the cost of manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view through a tape punch mechanism embodying a preferred form of the present invention.

FIG. 2 is an enlarged sectional bottom plan view taken along the line 2-2 of FIG. 1.

FIG. 3 is an enlarged fragmentary sectional plan view taken along the line 3-3 of FIG. 1.

FIG. 4 is a schematic wiring diagram of the means for controlling one of the punch solenoids.

FIG. 5 is a graph showing the reactive forces of the various springs and the resultant effect on the punch force.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring to the drawings, the punch mechanism comprises a series of cylindrical punches, i.e., 11, located in a line extending normal to the path of travel of a paper or similar tape 12. The punches are guided adjacent their upper ends in a guide block 13 and at their lower ends in a guide plate 14 attached to the block 13. The guide block 13 is suitably secured to a base plate 15.

A die block 16 is supported slightly above the guide block 13 to form a guide slot through which the tape 12 is guided over the die block. The tape 12 is fed endwise in the direction of the arrow A after each punching operation. For this purpose, a feed roller 17 is located directly below the path of travel of the tape 12 and is rotatably driven by a stepper motor 18 which may be of conventional construction. A rubber covered pressure roller 20 is rotatably supported at opposite ends by arms, one of which is shown at 21, pivotally mounted at 22 on a support member 31. Springs, i.e., 19, urge the arms 21 counter-clockwise, causing the roller to force the tape 12 into intimate frictional engagement with the feed roller 17.

Each punch 11 is notched at 23 along one side thereof to pivotally receive a circularly formed section 24 of a respective lever 25. The levers 25 are alternately pivotally supported by stationary pivot rods 26 and 27 which, in turn, are supported by spaced depending posts 28 formed on spring support members 30 and 31 which are suitably secured to the base plate 15. Spacers 32 are slideably mounted on the rods 26 and 27 and are interposed between adjacent levers to maintain the same in alignment with respective ones of the punches 11.

Each lever 25 has an upwardly offset extension 33 having an indentention 34 therein to form a socket for receiving the semi-spherical upper end of a relatively small diameter actuating rod 35 formed integral with the armature, not shown, of a respective solenoid 36.

Each lever 25 has an additional upwardly offset portion 37 which is connected to the lower end of a relatively light tension spring 38 anchored at its upper end at 40. This spring is effective mainly to normally hold its respective punch in its illustrated retracted position and to remove any clearances between the socket 34 and the upper end of its actuator rod 35. Thus, the springs 38 provide a minimum reactive force against the solenoids 36 and enable the latter to impart a maximum amount of kinetic energy to the punch linkage with a minimum amount of current Spring means are provided to decelerate the punches during and after the punching operation and to retract the same. For this purpose, a pair of cantilever leaf springs 41 and 42, see also FIG. 3, are interleaved with leaf type bolster springs 43 and 44, all secured to the support member 31 by screws 45. Each of the springs 41 and 42 have spring tines or fingers 46 which extend over the offset portions 33 of those levers 25 which are pivoted on the rod 26. The bolster springs are similarly formed but the tines 47 on spring 43 are considerably shorter.

Similar cantilever type springs 48 and 50, interleaved with bolster springs 51 and 52, are mounted on the support member and extend over the offset portions 33 of the levers 25 which are pivoted on the rod 27.

It will be noted that the lower cantilever springs, i.e., 41, are normally spaced above the respective .levers 25 to permit a certain amount of pre-travel of the punch, as indicated at 53, FIG. 5. This enables the net punch force to increase as shown by the graph line 54, under the impetus of a minimum solenoid force, before penetrating the tape 12. After the punch has partially sheared through the tape to a point indicated approximately at 49, the lever 25 engages the spring 41, thus decelerating the punch against the force of its solenoid and the momentum of the punch linkage. After a predetermined amount of over-travel of the punch into the die block 16, as indicated approximately at 65 and as determined by the thickness of the bolster spring 43, the spring 41 engages the much stiffer cantilever spring 42 which decelerates the punch linkage to zero speed and then immediately imparts a retracting kick" to catapult the punch and its linkage back toward their normal retracted positions shown in FIG. 1 where they rest against a pin 29 secured to the plate 15. The spring 41 continues this catapulting force to insure that the punch is withdrawn from the tape. Accordingly, the punches may be operated at a very high rate of speed with a minimum actuating force, thereby enabling the solenoids to be made relatively small without danger of overheating. Thus, also a group of such solenoids may be closely nested together as shown in FIG. 1 enabling the angular relationship between the various actuating rods 35 to be held to a minimum so that the actuating forces derived the various solenoids may be applied ap: proximately in line with the movement of the punches to reduce to a minimum any lateral frictional drag which might otherwise occur.

It has been found that best results and highest speeds are obtained when the springs 38, 41 and 42 have stiffness ratios related to each other on the order of magnitude of 1, 5 and 25, respectively.

Preferably, each solenoid 36 remains energized throughout the shearing movement of its punch and, after a predetermined amount of overtravel, is quickly deenergized so that the full force absorbed by the cantilever springs, i.e., 41 and 42, may be immediately used to retract the punch. For this purpose, the coil 56, FIG. 4, of each solenoid 36 is connected in series with the emitter collector circuit of an NPN transistor 57. The latter is controlled by a pulse generator 58 effective to provide a pulse 59 having a duration equal to the time required for the punch to advance through the pre-travel portion of its stroke and to completely shear through the tape. A Zenner diode 60 and a standard diode 61 are connected in series with each other across the coil 56 to provide a sharp cutoff of current through the coil.

A further feature of the invention resides in the construction of each of the levers 25 wherein the offset portions 33 and 37 thereof are located on the side of a line 62 passing through the pivot rods 26 and 27, nearest the tape 12. Thus, the forces exertedon each lever 25 by its spring 38 and actuator rod 35 tend to maintain the lever aligned in a plane parallel to the direction of movement of its punch. This reduces any tendency of the lever to twist or bind against its pivot bearing and eliminates the need for any bearing hubs on the levers.

I claim:

1. A punch mechanism comprising a punch,

a die member,

means for guiding a record medium over said die member, I

a device for advancing said punch from a retracted position through said record medium and into said die member,

a first spring means for applying a reactive force to said punch only when said punch has advanced partly through said record medium, and

a second spring means for applying an additional reactive force to said punch only when said punch has advanced completely through said record medium.

2. A punch mechanism according to claim 1 wherein said second spring means has a greater spring force than the spring force of said first spring means.

3. A punch mechanism according to claim 1 comprising a third spring means for continually urging said punch toward said retracted position,

said third spring means being weaker than each of said first and second spring means.

4. A punch mechanism according to claim 3 wherein said first and second spring means are capable of catapulting said punch to said retracted position independently of said third spring means.

5. A punch mechanism according to claim 4 wherein said first, second, and third spring means have relative spring strengths related on the order of magnitude of 5, 25 and 1, respectively.

6. A punch mechanism according to claim 1 wherein said punch advancing device comprises an electromagnetic device,

means for energizing said electromagnetic device to advance said punch,

and means for deenergizing said electromagnetic device only after said punch has penetrated through said record material,

said first and second spring means being effective to catapult said punch to said retracted position upon deenergization of said electromagnetic device.

7. A punch mechanism comprising a punch,

a die member,

means for guiding a record medium over said die member,

a device for advancing said punch through a punching stroke,

a pair of cantilever springs,

means supporting said cantilever springs adjacent one end of each thereof,

said device deflecting the free end of one of said springs only when said punch has advanced partly through said stroke,

and said device deflecting the free end of the other of said springs only when said punch has advanced further through said stroke.

8. A punch mechanism according to claim 7 wherein said springs are adapted to catapult said punch through said stroke to a retracted position.

9. A punch mechanism comprising a punch,

a die member,

means for guiding a record medium over said die member,

means for guiding said punch endwise toward and away from said die member,

a lever,

means pivotally supporting said lever for movement about an axis,

means forming a first pivotal connection between said lever and said punch,

a drive device for advancing said punch and said lever towards said die member from a retracted position,

means forming a second pivotal connection between said lever and said drive device,

said drive device being movable substantially parallel to the direction of movement of said punch and movable substantially normal to a line passing through said axis,

said second pivotal connection being located on the side of said line adjacent said die member and being located substantially along said line on one side of said axis,

a spring for urging said lever towards said retracted position, and

means forming a connection between said spring and said lever,

said last mentioned means being located on the side of said line adjacent said die member and on the side of said axis opposite from said second pivotal connection. I 10. A punch mechanism comprising a punch,

a die member, means for guiding a record medium over said die member,

means for guiding said punch endwise toward and away from said die member,

a lever,

means pivotally supporting said lever,

means forming a first pivotal connection between said lever and said punch,

a drive device for advancing said punch and said lever towards said die member from a retracted position,

means forming a second pivotal connection between said lever and said drive device,

said drive device being movable substantially parallel to the direction of movement of said punch and movable substantially normal to a line passing through said pivotal support,

said second pivotal connection being located on the size of said line adjacent said die member,

a spring for urging said lever towards said retracted position,

means forming a connection between said spring and said lever,

said last mentioned means being located on the side of said line adjacent said die member a pair of cantilever springs, and

means supporting said cantilever springs adjacent one end of each thereof,

said lever deflecting the free ends of said cantilever springs" seriatum during advancement of said punch.

11. A punch mechanism according to claim 10 wherein said lever co-acts with the free end of one of said cantilever springs during movement of said punch partly through said record medium and said lever co-acts with the free end of the other of said cantilever springs upon movement of said punch completely through said record medium.

i t I" 

1. A punch mechanism comprising a punch, a die member, means for guiding a record medium over said die member, a device for advancing said punch from a retracted position through said record medium and into said die member, a first spring means for applying a reactive force to said punch only when said punch has advanced partly through said record medium, and a second spring means for applying an additional reactive force to said punch only when said punch has advanced completely through said record medium.
 2. A punch mechanism according to claim 1 wherein said second spring means has a greater spring force than the spring force of said first spring means.
 3. A punch mechanism according to claim 1 comprising a third spring means for continually urging said punch toward said retracted position, said third spring means being weaker than each of said first and second spring means.
 4. A punch mechanism according to claim 3 wherein said first and second spring means are capable of catapulting said punch to said retracted position independently of said third spring means.
 5. A punch mechanism according to claim 4 wherein said first, second, and third spring means have relative spring strengths related on the order of magnitude of 5, 25 and 1, respectively.
 6. A punch mechanism according to claim 1 wherein said punch advancing device comprises an electromagnetic device, means for energizing said electromagnetic device to advance said punch, and means for deenergizing said electromagnetic device only after said punch has penetrated through said record material, said first and second spring means being effective to catapult said punch to said retracted position upon deenergization of said electromagnetic device.
 7. A punch mechanism comprising a punch, a die member, means for guiding a record medium over said die member, a device for advancing said punch through a punching stroke, a pair of cantilever springs, means supporting said cantilever springs adjacent one end of each thereof, said device deflecting the free end of one of said springs only when said punch has advanced partly through said stroke, and said device deflecting the free end of the other of said springs only when said punch has advanced further through said stroke.
 8. A punch mechanism according to claim 7 wherein said springs are adapted to catapult said punch through said stroke to a retracted position.
 9. A punch mechanism comprising a punch, a die member, means for guiding a record medium over said die member, means for guiding said punch endwise toward and away from said die member, a lever, means pivotally supporting said lever for movement about an axis, means forming a first pivotal connection between said lever and said punch, a drive device for advancing said punch and said lever towards said die member from a retracted position, means forming a second pivotal connection between said lever and said drive device, said drive device being movable substantially parallel to the direction of movement of said punch and movable substantially normal to a line passing through said axis, Said second pivotal connection being located on the side of said line adjacent said die member and being located substantially along said line on one side of said axis, a spring for urging said lever towards said retracted position, and means forming a connection between said spring and said lever, said last mentioned means being located on the side of said line adjacent said die member and on the side of said axis opposite from said second pivotal connection.
 10. A punch mechanism comprising a punch, a die member, means for guiding a record medium over said die member, means for guiding said punch endwise toward and away from said die member, a lever, means pivotally supporting said lever, means forming a first pivotal connection between said lever and said punch, a drive device for advancing said punch and said lever towards said die member from a retracted position, means forming a second pivotal connection between said lever and said drive device, said drive device being movable substantially parallel to the direction of movement of said punch and movable substantially normal to a line passing through said pivotal support, said second pivotal connection being located on the size of said line adjacent said die member, a spring for urging said lever towards said retracted position, means forming a connection between said spring and said lever, said last mentioned means being located on the side of said line adjacent said die member a pair of cantilever springs, and means supporting said cantilever springs adjacent one end of each thereof, said lever deflecting the free ends of said cantilever springs seriatum during advancement of said punch.
 11. A punch mechanism according to claim 10 wherein said lever co-acts with the free end of one of said cantilever springs during movement of said punch partly through said record medium and said lever co-acts with the free end of the other of said cantilever springs upon movement of said punch completely through said record medium. 